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Engine Specific Info and Questions => TDI Engine -General Info => Topic started by: nkb on January 08, 2007, 08:15:21 pm

Title: vnt25 on a Tdi-m
Post by: nkb on January 08, 2007, 08:15:21 pm
anyone running a vnt25 on a tdi? i might have found one for a good price but i don't want a complete dog in town from lag. i can already hit my max speed of 195km/h  at redline with my airesearch and my 1.9idi and thats with gps speed, the speedo said over 200...
Title: vnt25 on a Tdi-m
Post by: Benjamin on January 09, 2007, 05:59:41 am
my gt2559v normaly will run in the end of january or begin februari.
keep in mind not every vnt25 is asa big and powerfull as the turbo wich i bought.
you better can use the full GT number, alltough, early (wrong translation), in the 90's, turbo's were called vnt25, now we can recognise a vnt turbo if there is a 'v' in the end of the number (example: gt2052v, gt22v, gt2559v are vnt turbos, t25, gt2560, gt2560rs are not)
i think vnt25 turbo's from the 90's are not as powerfull as the GT series.

just in case you dont know  :wink:

DA-BRT should made a TDI with a gt2559v, 14mm plunger, i dont know wich EGT's he made, but it made 0,8bar(11psi)@1200rpm! it boosts 1,5bar(21psi) and makes a lot hp. but this one had special bearings...

Greetz, Benjamin
Title: vnt25 on a Tdi-m
Post by: DA-BRT on January 09, 2007, 06:19:04 am
Yeah, I'm still waiting for dyno plots from this engine.

We used a wastegate to save the turbo. I restricted It to 1.5bar. For the dyno they put it up to 1.8/1.9bar. That's one of the reasons they reached. 278hp/593Nm at the wheels. (Golf MK1 with adapted Audi A3 quattro driveline)
Title: vnt25 on a Tdi-m
Post by: Audi80 on January 09, 2007, 08:51:49 am
Quote
Yeah, I'm still waiting for dyno plots from this engine.

We used a wastegate to save the turbo. I restricted It to 1.5bar. For the dyno they put it up to 1.8/1.9bar. That's one of the reasons they reached. 278hp/593Nm at the wheels. (Golf MK1 with adapted Audi A3 quattro driveline)


 :D Wow. Tell more about this engine :D
Title: vnt25 on a Tdi-m
Post by: DA-BRT on January 10, 2007, 03:02:31 am
Well I worked a lot for racing companies, building up the engines. This combined with my love for diesel engines resulted in a small company for diesel modifications. I get a lot of people with a MK1 Golf, Jetta or Caddy that want a TDI engine in there car. Most of them don't want the electronics. (and I don't like electronics ;) )

A German friend of mine and ex-boss has been racing and sprinting for a long time and he wanted to make a killer diesel sprinter, money no issue. That's were I came in.

We discussed what the goal should be. (something around 250ph/500Nm) I told him that he would get problems on how to get the power to the road with the MK1 Golf. His thought: Lets adapt a 4-motion or Quattro driveline.

So it started about a year ago. He bougth the Golf and starting to strip it. Bought an Audi A3 1.8 20vt quattro with six speed gearbox as a donor car.
The whole driveline was send to Drenth transmissions to convert the gearbox to straigt gears, quaife differentials and some other stuf so the electronics could be removed. The Clutch is a Tilton multiplated one at the moment, but due to the fact that there is a lot of torque at very low rpm's we need to find something different.

All the engine parts are new or special fabricated. I bought a new engineblock (AFN) and head at Vege motors.

Took out all the internals putted the original Pistons on the 3D measuring table. And created a 3D point cloud. After that I created in Catia V5 the pistons the way I wanted them. There is oil cooling in de head, slightly different combustion chamber, The crooves were changed to adapt race rings and I changed the diameter to get a 2 liter engine. (Could go higher, but I don't think it's wise for the strength of the engineblock)
I took out a little bit more material to create more space for the valves. 28mm pistonpin.

Called up a couple of companies that are able to make this custom set of pistons and finaly JE (America) made them including slide coating on the side and thermal coating on the top.

Next step was getting a set of Rods. When I called JE how it was coming allong with the pistons. I asked him for a recommendation on Rods and since JE and Carrillo are cooperating the choice was easily made. He introduced me there and after 4 weeks I had my custom rods with oil feeding for the piston cooling.

Than I took the engineblock to a friend which is building up race engines almost all his life.
He was going to buildup the engine block to full race specs. I asked him to take of as little as possible from the crank, only that what is nessesary for balancing. He also changed the oil supply to drysump. After a couple of weeks it was ready.
Compliment from him to JE-Pistons. (The pistons are of high quality and pefectly balanced.)

Meanwhile I started on the cylinderhead. Started taking out the swirl from the intake (don't know the english name) Changed the valve seats to ones with a different angle. Took out some material to get clearance for future higer lift cam.

Then had contact with Kent cams if they could change a cam for us. Finaly it resulted in a new cam. The couldn't garantee the strength of the original modificated cam. Kent supplied also stronger valve springs

Fratelli Bosio supplied the nozzles and our local Bosch friend changed the injector bodies. (original Transporter T4 2.5TDI 220/300Bar)

We tried a Cummins fuelpump-body, but finaly we chose a modificated 1900TD (AAZ) one. Now it has got a 14mm plunger with standard camplate from an AHU TDI. The original plunger springs I changed to ones that are 120% of the orignal strength (don't want a flying camplate on the followers) The pump cover came from a Renault master pump with changed Govenor and Custom LDA pin.

For a turbo we bought a nice new VNT-25 and had the baerings changed. A friend of mine welded the exhaust manifolt. With a pre turbo EGT probe installed. Anc an flange for the wastegate.

The intake is a custom longrunner intake from aluminium. Studs on the front of the cylinderhead to support it.

As told last week they went to a place where they can dyno 4wd cars. The result was very good! For the third run they had 278hp/593Nm at the wheels.

I told my friend that I couldn't garanty him that this engine would last long..... Don't know what the original parts can handle.

As soon as I get to them I'll take some overall pictures of the car and dyno plot. (we live 200km's from eachother)
Title: vnt25 on a Tdi-m
Post by: RabbitGTDguy on January 10, 2007, 11:38:53 am
Amazing!!! Thats all I have to say....amazing :)

Joe
Title: vnt25 on a Tdi-m
Post by: Benjamin on January 10, 2007, 03:47:02 pm
how high are the EGT's?
wich compression ratio?

Greetz, Benjamin
Title: vnt25 on a Tdi-m
Post by: wolfsburgnut on January 10, 2007, 05:37:10 pm
SSSSSSSSSSSSSSWWWWWWWWWWWWWWWEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEETTTTTTTTTTTTTTTTTTTTTTTTTTTTT. :D  :D  :D  :D  :D  :D  :D  :D  :D  :D  :D  :D  :shock:  :shock:.  That is awesome.  And thanks for the details.
Benjamin,
My VNT20 sounds too small now.:)
Peter
Title: vnt25 on a Tdi-m
Post by: Tintin on January 10, 2007, 08:00:07 pm
Really beautiful work, i would like to see going this car  :wink:

It have there only something which worries me, the injection pump reliability? with a only 12mm plungeur and a original 10mm plunger spring, these spring combined with 12mm is too hard for the came plate, in less 2000KM i melted two came plate and roller + one third time i seized up a 12mm at 4000RPM  (.240mm nozzle)  ......???  14mm oufff!!!

That takes spring much softer,  those of 11mm VW or those of the majority of the 12mm are softer.

To compensate on the came plate floating,  it is better to use a came plate with more lift, and to lengthen the travel of the timing piston.

It is only my opinion, If not, I am impressed by your set-up   :wink:
Title: vnt25 on a Tdi-m
Post by: 935racer on January 11, 2007, 01:28:05 am
So was this one of Caddy's 14mm heads? from dieselspeedshop.com?? Sounds very cool I would love to see some pictures!
Title: vnt25 on a Tdi-m
Post by: DA-BRT on January 11, 2007, 02:11:22 am
Thanks for your comments!  :)

@Named Tintin: That's not good. I've been using the standard TDI springs for almost all my pumps.
The strange thing is that there are more than 10 that already drove more than 20dkm on this setup without any problems. Soon one of them will be converted from 11mm plunger to a 12mm. I'll feedback my findings on the pump.

I'll have a look at proper springs for this engine to keep it from damaging. Thanks for the tip!

@935racer: I bought it on Ebay a couple of months ago. It hasn't got any make or number on it. The guy that was selling it bougth it for his boat (It was a Cummins diesel engine it think) I didn't asked him for an address of de supplier, I'll ask it to him anyway for future buying.

Does anybody has any experience with the heads from Caddy? Durability/Quality?

As soon as I get to the car I'll make a photo report and post the dynoplot.
Title: vnt25 on a Tdi-m
Post by: SMOKEYDUB on February 11, 2007, 05:27:33 pm
ok i just read this post and that is alot of torque. If i was to convert that to ft lbs and correct me if im wrong but.. here goes nothing

593NM x 1/1.356 = 437 ftlbs of torque


 :twisted:

please correct me if im wrong but that is just F@#$ed UP!

my jaw has hit the ground and i know have to go to the hospital to put it back into place.
Title: vnt25 on a Tdi-m
Post by: shadowmaker on February 15, 2007, 04:10:57 pm
Nice piece of work! Really waiting to see that dyno.

Did you measure backpressure? Some years ago I couldn't use pressure above 1,5bar on my gt2559v, because backpressure went skyhigh even with big exhaust.

Now I'm using bigger vnt which seems to be easily capable for 2,0bar (haven't tried more because I think it has enough flow to cope with my current injection). It's just that in dyno it won't keep pressure up like in real world driving. Don't know why.
Title: vnt25 on a Tdi-m
Post by: malone on February 15, 2007, 05:23:45 pm
I just saw this thread and that TDI sounds impressive.

Quote
Fratelli Bosio supplied the nozzles


What size? Bosio should soon make 7-hole TDI nozzles (1 or 2 months). Presumably they will flow more than the Bosio Race 520 nozzles.

Quote
For a turbo we bought a nice new VNT-25 and had the baerings changed.


I really would like to know more about the different bearings. I am curious about this more than anything else. What VNT-25 is it? If you still have the part #.. Do you have a compressor map for that turbo as well? Or any GT22v?

Quote
Meanwhile I started on the cylinderhead. Started taking out the swirl from the intake (don't know the english name)


"Swirl" is the correct English name :) Did you take out all of the swirl shape so it ends up like a ported gas cylinder head? Or did you only take some swirl out? Does the engine normally idle at ~800 RPM and if so is it smooth or rough?

Last few questions for now:
0,8bar(11psi)@1200rpm is damned impressive although I don't know too much about that particular VNT-25. Sounds like the bearings are doing their job well (and your flowed head & manifolds, and 2.0 displacement). No turbo surge at all?

275awhp @ 1.8 bar is impressive too. Only 26 PSI and you're actually more concerned about lowering it to 1.5 bar! The TDI must have great overall airflow.

How is the exhaust smoke?

Thanks,
Mark
Title: vnt25 on a Tdi-m
Post by: SMOKEYDUB on February 15, 2007, 05:56:19 pm
I am very interested in any updates but more importantly that swirl in the cyl head.
Title: vnt25 on a Tdi-m
Post by: DA-BRT on March 06, 2007, 03:57:27 am
Sorry Guy's I've been away for a while (more important personal things)

This weekend I'm driving north to pick-up the fuelpump and make a copy of the dynoplot.

The engine had been taken appart by the owner to check for status.

@Malone: I took out almost the complete swirl chambre. I gained about 60% more flow.
Title: vnt25 on a Tdi-m
Post by: 935racer on March 06, 2007, 10:53:50 pm
Bert, any chance you could get pictures of the manifolds and the audi drivetrain stuffed in that rabbit? How much rpm are you spinning with that 14mm head?
Title: vnt25 on a Tdi-m
Post by: DA-BRT on March 07, 2007, 05:00:40 am
@935racer: It depends on where the engine is at the moment. I know the took is apart to check the internals. But I don't know if the allready put it back together.

Pictures of the parts in te Rabbit are not a problem.
Title: vnt25 on a Tdi-m
Post by: shadowmaker on March 07, 2007, 05:10:05 am
DA-BRT: Any Bosch number for that 14mm head?

I still have little swirl left, because I thought it will be better for mileage as my van is in everyday use.
Title: vnt25 on a Tdi-m
Post by: DA-BRT on March 07, 2007, 05:50:59 am
@Shadowmaker: After this weekend I got the pump back for changing. I can't remember that there was a number on the plunger/head. But I closely look at it. I bought this head from Ebay.de and I didn't said it was a Bosch head or another make.
Title: vnt25 on a Tdi-m
Post by: Benjamin on March 07, 2007, 11:34:50 am
i wonder if Bosch ever made a 14mm plunger, i thought its only after market

Greetz, Benjamin
Title: vnt25 on a Tdi-m
Post by: RabbitGTDguy on March 07, 2007, 09:50:32 pm
yah, I'm wondering as well. I believe I had read/looked elsewhere and Bosch only made up to a 12mm unit. I believe the only 14mm heads I've seen on the aftermarket were the chinese ones...

Joe
Title: vnt25 on a Tdi-m
Post by: 935racer on March 07, 2007, 10:06:21 pm
Bosch does in fact only go up to 12mm. I have a 14mm head that I bought from dieselspeedshop.com but I havent installed it yet. How high did this pump rev that you built? I am worried about siezing mine. Also what was the reason for engine dissasembly.
Title: vnt25 on a Tdi-m
Post by: DA-BRT on March 08, 2007, 04:00:06 am
@935racer:

The engine is still in his brake in period (i don't know if I describe it correctly) The shiftlight was set at 4500RPM. In the sixt gear it went through 5000RPM easily.

A temperature gauge on the pump would't be any luxury.

The reason for dissasembling the engine was becayse of all the new parts and a racespec. build engine. It's very standard to take it apart after 1500 / 2000 km to check wear marks.
Title: vnt25 on a Tdi-m
Post by: malone on December 19, 2007, 02:30:30 pm
More updates! How's the engine running?

Since removing the complete swirl chamber almost completely, how smooth is the engine at low RPMs?

Pictures and dyno?
Title: vnt25 on a Tdi-m
Post by: Helliouse on February 22, 2008, 12:24:46 pm
Bump...this is to good not to...